Hi all. I follow this thread with great interest. I (of course) have never built any soundboard. My experience is limited to having replaced only one in my life, with much success must I add. It was a Ciresa pannel ribbed by a friend of mine (combination of CC and RC), and as close a copy as we could figure out of the original, which was a 1871 Bechstein board, 8 mm thick all over the surface, with fanned ribs, and floating trebble side. But what I did when I recieved the board, and before ribbing it, was puting it upright and simply knocking it with my fist, right out of the box. It made a certain not unpleasant sound. Then, I leaned with all my weight on it, and knocked again. The sound was dramatically better, this is, the parts of the sound that had nearly a recognizable pitch had a higher pitch, and their vibrations lasted definately longer, making the whole sound much more pleasant and singing. I then imagined (intuitively) that the board needed some compression to make a good sound, just as the strings need tension to sound well. It made me think also that crown and downbearing are meant only to achieve this compression, favorable to good sound. This apparently tends to speak against the RC&S way of building soundboards, unless you imagine that ribs contribute much to sound wave production (I can't imagine how the whole system stiffness matters more than the pannel stiffness, as I think for now it is still the pannel's vibrations that matter more when it goes about transforming string energy into acoustic energy). But then, as a friend of mine pointed out, in old flat boards, there must not be that much compression left in the panel. Yet, some do sound very good (in my world at least). This tends to cast doubt on what I just said. As always, my general feeling is that things are not quite simple. Please forgive my unauthorized intervention, meant only to raise interesting comments. Best regards. Stéphane Collin.
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